1. Field of the Invention
Embodiments of the present invention relate to a keyboard apparatus for the performance of music and, in particular embodiments, to a keyboard apparatus with which the input of performance information and the like to a computer is possible.
2. Related Art
In the past, electronic musical instruments have been proposed that are furnished with a keyboard and a sound source, and with which it is possible to easily play the keyboard and enjoy music. On the other hand, using a personal computer, the creation of new pieces and the editing of already existing pieces can be carried out. In addition, personal computers possess the capability to produce musical tones by means of the execution of programs that are known as so-called soft synthesizers, and keyboard apparatuses with which it is possible to carry out a performance with a feeling such as that of a personal computer keyboard for the input of letters and the like in order to input performance data are desired.
For this kind of keyboard apparatus, one that is especially compact and thin and, moreover, that has a key stroke that is short compared to an ordinary keyboard but accurately detects the key pressing speed and the key releasing speed is demanded.
For example, with the keyboard apparatus that is disclosed in Japanese Laid-Open Patent Application Publication (Kokai) Number Hei 9-274482 (Patent Reference 1), a thin type keyboard apparatus is disclosed where at least an octave of keys is formed as a unit in which a plurality of white keys and black keys are formed in a process in which the keys are pressed from a thin steel plate,and the intervals between the mutually adjoining keys are removed by excising processing.
In addition, in Japanese Laid-Open Patent Application Publication (Kokai) Number 2002-62876 (Patent Reference 2), a keyboard apparatus is disclosed in which a key unit that comprises the key main body, the key support section, and a connecting section that connects the key main body to the key support section so that the key is free to swing, is formed as one body with a resin. With the key unit, since the resin is poured from the rear end of the key main body or the connection section at the time that the unit is formed, the flow of the resin in the mold becomes uniform and it is possible to improve the strength of the key.
However, in a keyboard apparatus that has been disclosed in Patent Reference 1, since a plurality of white keys and black keys are processed by press processing in a single unit from a thin steel plate and following that, the keys are formed by the intervals between the mutually adjoining keys being removed by excising processing, the side walls do not exist for the keys. Accordingly, because, in particular when a white key is pressed down, the space between the key and the adjoining key is opened greatly, the appearance is poor and, together with this, because the comer of the key that adjoins the key that has been pressed down may be entangled by the finger, there has been the problem that it is not possible to carry out an agile performance.
In addition, with the invention that has been disclosed in Patent Reference 2, the operability of the keys can be improved, but there has been the problem that it is not possible to form the keyboard apparatus compactly and thin.
In addition, the rubber switch of the keyboard apparatus that is disclosed in Patent Reference 1 can detect the key pressing speed, but the touch feeling is poor. There have especially been the problems that the feeling of the force pushing back against the finger at the time that the keyboard has been pressed is not satisfactory and, together with this, chattering is produced when the fixed contact and the moveable contact come into contact and it is difficult to accurately detect the key pressing speed. In particular, in order to detect the key pressing speed, it is configured such that in response to the pressing down of a key, first, the first moveable contact and the first fixed contact come into contact and, next, the second moveable contact and the second fixed contact come into contact. Because of this, after the first moveable contact and the first fixed contact have come into contact, even during a time that the key is pressed down further and the second moveable contact and the second fixed contact come into contact, it is necessary that the first moveable contact be stabilized and the pressing on the first fixed contact be continued.
However, after the first moveable contact and the first fixed contact have come into contact, distortion is produced by a process in which the key is pressed down further and the area that the first moveable contact presses is deformed and chattering occurs. In particular, when the second moveable contact comes into contact with the second fixed contact and the area that is pressed by the second moveable contact begins to deform, the first moveable contact is affected.
In addition, there is a need to provide a click sensation for the key, but it is also necessary that the key rotate smoothly to the lowest portion after the click sensation has been imparted and a keyboard apparatus having a satisfactory operating sensation be made.